Diffusion in the Lungs
Diffusion is a _______________ in which substances move from an area of _____________
concentration to an area of __________ concentration. In the alveoli, _____________ of gases takes
place.
When _____________________ blood from all parts of the body reaches the ____________, it has a
____________ concentration of carbon dioxide (CO2). Since the concentration of __________ in the
alveoli is __________ compared to that in the blood, CO2 diffuses from the blood into the alveoli.
The concentration of O2 is much _____________in the alveoli and it diffuses into the blood making the
blood ________________. Oxygenated blood (rich in oxygen) is transferred to the ________________
from where it gets pumped to all parts of the ____________.
CO2 gets released out of the lungs when a person _________________.
Word Bank
lower
exchange
deoxygenated
High
body
process
heart
alveoli
oxygenated
exhales
low
higher
CO2
Rosa’s Classroom
Diffusion in the Lungs
Diffusion is a process in which substances move from an area of high concentration to an area of low
concentration. In the alveoli, exchange of gases takes place.
When deoxygenated blood from all parts of the body reaches the alveoli, it has a higher concentration
of carbon dioxide (CO2). Since the concentration of CO2 in the alveoli is lower compared to that in the
blood, CO2 diffuses from the blood into the alveoli.
The concentration of O2 is much higher in the alveoli and it diffuses into the blood making the blood
oxygenated. Oxygenated blood (rich in oxygen) is transferred to the heart from where it gets pumped
to all parts of the body.
CO2 gets released out of the lungs when a person exhales.
Word Bank
lower
exchange
deoxygenated
High
body
process
heart
alveoli
oxygenated
exhales
low
higher
CO2
alveoli
capillary
CO2
O2
Oxygenated blood
Deoxygenated blood
Rosa’s Classroom